1. Field of the Invention
The present invention relates to a wide field of view optical magnifying system and more particularly to an eye loupe having a magnification power of 4 (4.times. magnification).
2. Description of Related Art
Visual inspection tools are used in several industrial fields to inspect components for defects which cannot be seen with the naked eye. Many industries have stringent magnification specifications. In the soldering industry and especially in the aerospace circuit board industry, the solder connections must be inspected to meet desired specifications. Visual tools, such as magnifying eye loupes, are used to increase the apparent size of the solder connection viewed. This increase in size better enables an inspector to see and determine whether or not the solder connection meets desired specifications. Other applications will become apparent which utilize magnifying devices for inspection where inspection with the naked eye is inadequate.
Prior magnifying optical systems having 4.times. magnification exist in the field. These prior magnifiers generally have one to three lens elements and have several disadvantages. The prior eye loupes generally are not true 4.times. magnifiers and generally have a magnification power of less than what is specified on the magnifier. The magnifiers generally have a small field of view, which view causes severe eye strain in just a short period of time. The viewing distance between the user's eye and the object is generally very short. This close viewing range causes the user to hold the viewed object in close proximity to his face. Generally, the prior eye loupe lenses have distorted imagery as the view traverses from the center to the peripheries of the field of view. The prior lenses are somewhat heavy, have poor resolution, and have chromatic aberrations. Also, prior magnifiers generally limit the eye resolution along the axis of the magnifier. Thus, there is a need in the art to provide an optical magnifying system, having a wide field of view at 4.times. magnification, and which the operator can easily control during use.